Like this question, I have a 'Signature Hardware' pedestal sink to install, which does not come with a bracket. They expect you to use "lag bolts" into the wall.

I have access to a Kohler 64839 bracket -- used by the previous sink in the same location which looks like it could work. The previous sink could be held up just by the wall bracket fastened to the wall -- the pedestal was semi-decorative, only.

I think the bracket was previously installed using ordinary screws, but I don't remember if there was blocking inside the wall or wall-anchors were used. Now, it's too late: there is freshly installed tile in the way. Room view

What are my next steps? I think they are:

(1) 'Dry set' the sink and carefully mark the wall where holes should be.

(2) Drill exploratory hole(s) in the tile using a diamond or carbide-tipped drill, and see if I find blocking.

If I don't find blocking in the wall where I drill the holes, then

(a) I can't use my favorite kind of drywall anchor, since it needs to go through tile; and wall anchor

(b) I guess I need to fallback to toggle bolts or 'molly bolts', not hanger bolts or lag bolts. The goal here is to secure the sink to the wall, so that it won't fall when people sit or lean on it. What size is needed?

Are those the right steps?

View of the sink, showing rim the bracket could attach to, and additional 3/4" (19mm) holes for large bolts/screws to pass thru: View of sink underside

A different manufacturer's method uses ''hanger bolts'' -- if you don't have blocking, surely this can't work: Instruction manual from a different manufacturer

  • I don't understand the question. Are you basically certain you can attach the sink using the supplied (or self-provisioned) lag/hangar bolts, but you're unsure of the stud location? Can you find the studs on the other side of the bathroom wall?
    – AdamO
    Jan 30, 2023 at 21:33
  • You should be able to locate the studs on the non tiled portion of the wall. The studs should go floor to ceiling. I think toggle bolts will be fine but I'm not posting as answer, I'll let one of the bath and tile experts weigh in. Jan 30, 2023 at 21:35
  • Thank you: yes, I definitely know where the vertical studs are, using a stud finder. But the stud finder doesn’t work through tile to check if there is horizontal blocking. Jan 30, 2023 at 23:00
  • What's on the other side of the wall?
    – Huesmann
    Feb 2, 2023 at 19:27

1 Answer 1


A sink needs to be attached to studs, or, more often, to wood blocks that are attached to studs. There's no way to get around this. If you try to hang it from drywall, then it will fail, so forget about using drywall anchors or toggle bolts.

There are two typical ways to hang a sink: with hanger bolts that go through the mounting holes in the sink (like the illustration you posted) or with brackets that attach to the wall, and then hook under a lip on the backside of the sink (see below). It looks like your sink supports both methods.

enter image description here

You have the right idea with the exploratory holes. You'll need a diamond bit to get through the tiles. If there was a wall-mounted sink in that spot previously, then there's a very good chance that there is blocking in the wall already. If so, then use one of the two methods above. If not, you'll have to get creative. Depending on what's on the other side of the wall, you might be able to open up the wall and install the blocking from the other side. Or you might be able to use a wide bracket, like the ones below, as long as you can position it over a stud.

enter image description here

enter image description here

  • 1
    Thanks Mike. This makes a lot of sense. I guess the key is to drill the tile as a clearance hole and stop as soon as the bit reaches the end of the drywall. The threads will need to engage the blocking (🤞) so the thru-hole (larger diameter) needs to stop at that point. Jan 31, 2023 at 3:01

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